1. Field of the Invention
The present invention relates to complex oxide materials and high energy-density lithium batteries in which a complex oxide material is used as a cathode active material for lithium secondary batteries. Particularly, the invention relates to lithium secondary batteries for automotive applications.
2. Background Art
JP Patent Publication (Kokai) No. 2000-77072 A discloses an example of conventional lithium secondary batteries in which attempts are made to achieve higher levels of safety by employing a complex oxide consisting of Li and Ni, namely, a mixture of lithium nickelate and lithium manganese oxide, as a cathode active material that contains at least Li and Ni. However, no batteries have so far been obtained that can sufficiently satisfy both the safety and long-life requirements for electric vehicles.